The military ammunition (for example, artillery shells, bombs, landmines, and underwater mines) generally has a structure where a shell made of steel contains therein a bursting charge.
The ammunition is treated by blasting, for example. The treatment method by blasting requires no disassembling operation. This provides adaptability to a disposal not only of favorably preserved munitions, for example, but also of munitions hard to disassemble because of its deterioration over time, deformation, or the like. Further, when bombs including chemical agents hazardous to human bodies are treated by the treatment method, most of the chemical agents are decomposed under the ultra-high temperature and ultra-high pressure generated by explosion. An example of such a blast treatment method is disclosed in Patent Document 1.
According to the method disclosed in the Patent Document 1, a treatment subject is put in a container with an ANFO explosive around it, and the container is wrapped around by a sheet-shaped explosive having a greater detonation velocity than the ANFO explosive. When a predetermined end portion of the sheet-shaped explosive is initiated, the sheet-shaped explosive progressively detonates in a given direction, and the detonation of the sheet-shaped explosive triggers the ANFO explosive to detonate progressively in a given direction. The detonation thereby caused breaks the shell of the object and detonates the bursting charge contained therein so that the object is blasted.
According to the method, the detonation vector of the ANFO explosive filled inside of the sheet-shaped explosive is directed inward by the detonation of the sheet-shaped explosive. When the detonation vector of the ANFO explosive is directed inward, the detonation vector of the bursting charge in the shell, which was originally directed outward, is directed inward. This slows down fragments of the shell scattering outward due to the explosion of the bursting charge.
Depending on the type or density of the bursting charge contained in the treatment subject, the velocity of detonation propagation of the bursting charge may be very high. If the conventional blast treatment method described above is employed to detonate the bursting charge thus characterized, the detonation of the bursting charge may propagates faster than the detonation of the ANFO explosive. Then, the bursting charge detonates before the ANFO explosive provided on its outer side detonates, and as a result, it increases the risk of scattering the shell fragments outward.
Patent Document 1: Japanese Patent Application Publication No. 2005-291514